We get quite a few requests from folks to explain how to get started with Amateur Radio Satellites. Requests for information on how to build a computer-controlled ground station for Linear Satellites are also pretty common. I recently got such a request from our CWA class so I decided to put together a session on this topic.
We covered a number of topics and demonstrations during the session including:
How to put together a simple station and work FM EasySats with HTs and a handheld antenna
A recorded demonstration of some contacts using FM EasySats
How-to build a computer-controlled station and work Linear Transponder Satellites
Fixed and Portable Satellite Station Antenna options
A recorded demonstration of some contacts using Linear Satellites
Winter Field Day 2020 is almost here! A few weekends ago, several of us got our QTH to complete the final station test for our planned 5O operation in Winter Field Day (WFD). Activities including setup and testing of a new, Portable Networking Pod and three of our five planned Winter Field Day stations. We are planning to use the N1MM+ Logger in a networked configuration this year…
This article covers equipment and networking aspects of the Nashua Area Radio Society’s planned 5O setup for Winter Field Day 2020. All of our stations will use the N1MM+ Logger to support SSB Voice, CW, and Digital modes.
We are continuing to make progress on our preparation for VHF+ Operations at Winter Field Day (WFD) 2020. We had a lot of fun on the VHF+ bands at WFD 2019 and we are planning to add some more bands for our operation this year. We’ve assembled a portable mast system to put us on 3 new bands…
We’ve been busy with preparation for Winter Field Day 2020. My part of this project is to increase our participation in operations on the VHF+ bands (6m and above). We are accomplishing this with a 30 ft push-up mast, some new antennas, and using Transverters for the 1.25m and 33cm bands. You can read more about our preparations and the equipment that we will be using on the VHF+ bands via the link above.
We continued to test our Portable Satellite Station 4.0 as part of AMSAT’s 50th Anniversary Celebration WAS Activations. You can read about the activations and our station’s performance via the link above. Overall, we were pleased with how the portable setup performed. The weakest link was the downlink performance of our antenna system. We are working on some ideas to improve this element of our setup – more to come on this project…
Portable Satellite and Grid Square Activation Station
We were up on Mt. Washington here in New Hampshire this past weekend and we decided to use the SOTA activation as a test for our updated Portable Satellite Station 4.0. It turned out that the station was also a great SOTA and Grid Square Activation station for terrestrial contacts.
A Solar-Battery Power system capable of operating the station continuously for a full day
A laptop computer for Satellite Tracking and Doppler correction
Portable Antenna System
Elk Antenna on Tripod
We decided to keep our antenna system simple and quick to deploy. We choose a portable 2m/70cm antenna from Elk and mounted it on a camera tripod. A carpenter’s slope gauge is used as an elevation indicator and our iPhone serves as a compass to point the antenna in the azimuth direction. A weighted bag, Bungie cord, and a tent stake anchor the tripod in the windy conditions on the mountain. A 15 ft length of LMR-240uF coax with N-connectors makes the connection between the antenna and the rest of the station.
Station Transceiver and Supporting Gear
Portable Station Transceiver and Preamps
We decided to mount the station Transceiver and supporting gear on a piece of plywood to make it easy to transport and setup. The components from lower-right moving counter-clockwise include:
The preamps are powered and sequenced by the IC-910H through its coax outputs. The 70cm side of the second diplexer is used as a filter to prevent transmissions on 2m uplinks from de-sensitizing 70cm downlink signals.
Portable Station Electronics
The use of the mounting board for all of the components allows the station to deployed quickly and helps to ensure reliable operation.
We used a MacBook Air Laptop running MacDoppler to control the transceiver’s VFOs (via a USB CI-V cable). MacDoppler also provided azimuth and elevation data used to point the antenna during satellite passes.
Portable Solar-Battery Power System
Powering a 100w radio in a way that allows continuous use for a day can be a challenge. It’s important to do this in a way that does not generate noise so we do not disturb others trying to enjoy the outdoors. We met all of these needs using a combination of solar power and batteries.
Portable Solar Power
The primary source of power comes from a pair of 90w foldable solar panels from PowerFilm. The panels are wired in series and connected to an MPPT Charger which charges a pair of batteries. This approach allows the system to provide usable power when it is cloudy and the voltage output of the solar panels drops.
We use a pair of A123 10 Ah LiPo battery packs to supply high-current capacity when transmitting. The solar-battery combination is capable of maintaining full battery voltage while supporting the continuous operation of our station for a full day.
The MacBook Air Laptop batteries are adequate to operate the station during the available satellite passes. We have a 12V DC to 120 VAC inverter which can power the computer from our solar battery setup if needed.
View from Mt. Washington Summit
Our portable station did very well during its initial test! I had to move the antennas and operate the station by myself on this activation which limited my ability to make a large number of contacts during the limited number of satellite passes that were available. Still, I was able to make 6 solid contacts through AO-91 and AO-85 while on Mt. Washington. I did not have a suitable linear satellite pass to make contacts but I was able to hear the EO-88 beacon with no problems and confirm that the doppler correction system was working well.
The station also put in a great performance visa-vie 2m terrestrial contacts. We made a total of 70 contacts using 2m FM and USB! We received many good signal reports with our longest contacts being some 275 mi from our location. We also worked stations on four other SOTAs this way.
Learnings and Next Steps
Our station exceeded my expectations during our initial test on Mt. Washington – especially in terms of the number of Terrestial Contacts that I was able to make with it. I did notice that the transmit side of the system was quite a bit stronger than the receive side. This is an indication that a better antenna would help.
We changed the antenna polarization to vertical for 2m FM contacts and to horizontal for 2m USB contacts. This helped the receive side performance quite a bit.
I found that a headset was essential for satellite and terrestrial weak-signal operation in USB mode. I was able to use the hand microphone and the radio’s speaker for most of the 2m FM contacts that I made. This gave interested onlookers a chance to experience Amateur Radio.
Satellite operation would have been much easier and more productive with a helper to handle pointing the antenna while we operated. This improvement will need to be coupled with a headset/speaker combination that allows the person that is pointing the antenna to hear the quality of the downlink while moving the antenna and finding the best polarization.
I am looking forward to doing some grid-square activations using our upgraded portable station. It was a pleasant surprise to find as much interest in Terrestial contacts on the 2m band as we did. The Nashua Area Radio Society does several SOTA activations each year and I am looking forward to using that station for these as well.
Here are links to some additional posts about our Satellite Station 4.0 Projects:
The Nashua Area Radio Society always brings something new to each Field Day that we do. In addition to our Computer Controlled Satellite Station, we will be adding a state of the art Weak Signal Antenna System and Station to our Field Day 2019 lineup. Our VHF Station will use a dedicated 40 ft Tower with Tower Mounted Preamps and low-loss feedlines. You can see what is going on at Field Day 2019 on 6m and above via the preceding link.
What goes into an 11A Field Day? Well, for starters, 13 stations! We got together at AB1OC/AB1QB’s QTH a couple of weekends ago to set up ALL of our Field Day stations at once and test them together. Here’s a rundown of our final Field Day Station Test…
The Nashua Area Radio Society does a pretty big Field Day Operation each year. We will be 11A for Field Day 2019 with 4 towers up. Did you ever wonder what goes into pulling off a Field Day this large? Well, it’s all about planning and preparation. Take a look at the article above to see some of the preparation that we are doing for Field Day 2019.
The Nashua Area Radio Society participated in Winter Field Day for the first time this past weekend. We put up a 40 ft tower and we were QRV on all allowed bands from 160m through 2m and 70cm. Our station was a four transmitter one and we produced a great score during the 24-hour operating period. Winter Field Day presents some unique challenges that we did not encounter during Summer Field Day.
We put together a station for 160m for the first time as well as some other new things. You can read all about our approach to a station and operating for Winter Field Day via the link above.
It’s almost impossible to field an effective 160m station with only a Transmit antenna. Transmit antennas typically are too noisy for effective operation on the low bands. We decided to try a Beverage On The Ground antenna for the receive side of our 160m station. This proved to be a great choice.
Icom IC-7300 Transceiver
We’ve been using the Icom IC-7300 Transceiver almost exclusively for our Field Day stations for the last several years. Many of our members have this rig and its performance and excellent ergonomics make it a great choice. The problem was that we needed a receive antenna input to make the IC-7300 work with our 160m station plans.
This mod is simple and is super easy to install. It took me about 30 minutes to do the mod and it worked great. Removed the jumper and you have a separate Rx antenna input. Put the jumper back and the radio performs as stock.
KD9SV Variable Gain Preamp
Rx antennas typically benefit from the inclusion of a low-noise preamplifier to boost the relatively weak signals from the antennas. We also want a bandpass filter to protect our 160m radio from overload and potential damage which might eliminate from the other transmitters in our Winter Field Day setup. The KD9SV Variable Gain Pre-Amp filled the bill nicely.
KD9SV Front End Saver
We also added a KD9SV Front-End Saver to ground the input to the preamplifier/radio combination when the IC-7300 goes into transmit to further protect the electronics from overload or damage when transmitting on 160m.
An RBOG Antenna such as our must be well grounded at each end. This was accomplished with a pair of 4 ft ground rods and three 50 ft long radials at each end in a crows-foot configuration. All of the need components for the antenna including interconnect and power cables, ground straps, and the electronics were package in a case to keep everything together.
RBOG Antenna Installed In The Field
The photo above shows one end of the RBOG antenna installed in the Field. You can see both the radials and the feed line transformer attached to one of the ground rods. Our antenna was fed with 300 ft of 75-ohm flooded coax terminated with F connectors. The direction of the antenna can be easily reversed by interchanging the feed line and the 75-ohm terminator at this end of the antenna.
Station Test at our Winter Field Day
We decided to set up and test the receive side of 160m station at our Winter Field Day site in advance to work out any installation issues and to gauge the system’s potential performance. Unfortunately, we ended up doing the test in the middle of the day when 160m was basically dead. We also tested the antenna on the AM broadcast band which is just below 160m and we heard 2-3 AM station on every AM frequency in the middle of the day! This was a very good sign of what was to come…
Setting up our 160m Transmit Antenna was the first order business for the Wire Antenna Team at Winter Field Day. We put up a 50 ft guyed push-up mast used a pull-rope to hoist the 160m Tx Antenna’s Balun to about 48 ft. We used an air cannon to shoot ropes through two tall trees at the ends of the antenna and we were able to get it close to flat-topped.
160m Tx Dipole SWR
After a little bit of careful tuning, we ended up very pleased with the end result. We had over 60 kHz of usable Tx bandwidth at the bottom of the 160m band. We used the antenna as high as 1.838 MHz during Winter Field Day and it performed great.
So how did the combination perform for us? Well, we made a total of 133 CW contacts on the 160m band during the 24-hour Winter Field Day period with the longest one being to Missoula, MT – a 2,100 mi contact from here in New Hampshire. This is not bad for 100W and portable antennas on Top Band!
Like many memorable events in our lives, our journey towards the Hudson Memorial School ISS Crew Contact began in a modest fashion with a telephone call from Dan Pooler at Hudson Memorial School in Hudson, NH. Dan had been to Space Camp where he heard about an ARISS Crew Contact from … Continue reading Journey to an ISS Crew Contact →
Our project to help the students at Hudson Memorial School in Hudson, NH make a contact with an astronaut on the International Space Station via Amateur Radio is a memory now. The link above is to an article about the more than year-long journey that led to this once in a lifetime experience. I hope that you enjoy it and don’t miss the video of our contact towards the end of the story.